There's been some great advances in research on losing excess weight that have came out over the last five to ten years. Here are some notes about what we now know...
1.) Bacteria Imbalance in the gut...research shows that probiotics may assist with weight loss. Probiotics aid in digestion, may help reduce inflammation, and generally help promote a healthy and balanced immune system.
2.) Exposure to environmental toxins from plastics, pesticides, fuel derivatives, and other industrial residues can complicate diabetes, and obesity and account for missing links. A new term has been made for these chemicals: obesogens.
There's been increasing discussion going on about how obesity and diabetes are not just issues of "energy in, energy out" anymore. This model does not account for "skinny fat people" and types of fat such as belly fat and "subcutaneous fat" in the arms and legs.
Toxins are fat-soluble, and become insulated in fat as a natural protection...their release has been shown to slow weight loss and may account for weight loss plateaus. Some individuals looking to lose weight, may require a few cycles of "cleanses" to tip the balance in favor of weight loss.
3.) Low-level exposures to these chemicals over time have been shown (at least in correlation) to be associated with diabetes, obesity, cardiovascular disease, Alzheimer's (now considered by some a Type III diabetes), and mitochondrial insufficiencies ("battery voltage" to deal with stress, toxins, energy in general).
3.) Chronic high levels of cortisol from stress, promotes central fat (around the waist) as well as promotes inflammatory cascades associated with other chronic disease. Belly fat is often the first to come and the last to go. Ridding it may be helped by a low-Glycemic Index diet (no white sugars, white flours, white, starchy vegetables), stress reduction techniques like deep breathing, as well as high-intensity interval exercise (20-30 minute workouts to exhaustion, or moderate intensity for 60 minutes).
4.) Support is rising for a "Slow-Carb" diet, with some allowed cheat days/cheat meals. This means being extra careful of all sources of sugar and carbs including fructose from fruits (excepting tomatoes/avocadoes), while allowing yourself a binge day while still being mindful of food sensitivities and allergies.
It also DOES NOT mean just eating steak and butter for meals, but ensuring loads of greens and a variety of vegetables with moderate protein spaced out throughout the day. This food plan accounts for basic needs with herbs and botanicals providing added support, arguably just as nature intended.
5.) Timing of meals is just as important as composition, and the order and rate of food consumption can make a significant different. A similar food plan can be found through Paleo Diet advocates like Robb Wolf and Mark Sisson. Fresh-squeezed lemon juice and a touch of cinnamon before meals for instance can significantly modulate insulin and glucose balance in the blood.
6.) Subclinical Hypothyroidism (thyroid blood values look "normal", but still tired, gaining weight, thinning hair, etc), this can come back to adrenals (stress glands), gluten-sensitivity (even in those with negative bloodtests), other unknown food sensitivities, and toxin exposure.
All of these processes are interconnected, working on one, can help modulate another! Reducing stress helps modulate blood sugar, helping blood sugar helps modulate stress, and so on. I'm not giving labels to any new diseases, disease is adaptations of the body to stress.
Notice I never mentioned calories.